Work machine remote control system

ABSTRACT

A work machine remote control system includes a sensor data reception unit that receives detection data of an attitude of working equipment included in a work machine operated by an operation signal from a remote place, an alarm control unit that outputs an alarm control signal when it is determined, based on the detection data, that the working equipment is approaching or has reached an end position in a movable range, and an alarm device that is provided in the remote place and outputs an alarm based on the alarm control signal from the alarm control unit.

FIELD

The present disclosure relates to a remote control system of a work machine.

BACKGROUND

In a technical field related to a work machine, a technique for remote control of the work machine is known. In the remote control of the work machine, an image of a work site where the work machine operates is captured by an imaging apparatus. The image captured by the imaging apparatus is transmitted to a remote place and displayed on a display apparatus disposed in the remote place. An operator in the remote place performs the remote control of the work machine while viewing the image displayed on the display apparatus. Patent Literature 1 discloses a technique in which the imaging apparatus is disposed in a cab of a swinging platform to capture an image in front of the cab.

CITATION LIST Patent Literature

Patent Literature 1: JP 2019-068236 A

SUMMARY Technical Problem

A work machine performs work using working equipment. In the work using the working equipment, an impact may act on the working equipment. It is difficult for an operator in a remote place to recognize the impact acting on the working equipment. Therefore, there is a possibility that the operator in the remote place performs remote control that results in applying an excessive impact to the working equipment. When the excessive impact acts on the working equipment, deterioration of the working equipment may be accelerated.

It is therefore an object of the present disclosure to make the operator in the remote place recognize an impact that will act on the working equipment.

Solution to Problem

According to an aspect of the present invention, a work machine remote control system comprises: a sensor data reception unit configured to receive detection data of an attitude of working equipment included in a work machine operated by an operation signal from a remote place; an alarm control unit configured to output an alarm control signal when it is determined, based on the detection data, that the working equipment is approaching or has reached an end position in a movable range; and an alarm device provided in the remote place and configured to output an alarm based on the alarm control signal from the alarm control unit.

Advantageous Effects of Invention

According to the present disclosure, it is possible to make an operator in a remote place recognize an impact that will act on working equipment.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a work machine remote control system according to an embodiment.

FIG. 2 is a perspective view illustrating the work machine according to the embodiment.

FIG. 3 is a side view illustrating the work machine according to the embodiment.

FIG. 4 is a diagram illustrating a remote control room according to the embodiment.

FIG. 5 is a schematic diagram illustrating a hydraulic system of the work machine according to the embodiment.

FIG. 6 is a functional block diagram illustrating the work machine remote control system according to the embodiment.

FIG. 7 is a schematic diagram illustrating a movable range of components of working equipment according to the embodiment.

FIG. 8 is a diagram illustrating a process by a first image processing unit according to the embodiment.

FIG. 9 is a diagram illustrating a process by a display control unit according to the embodiment.

FIG. 10 is a diagram illustrating a process by an alarm control unit according to the embodiment.

FIG. 11 is a flowchart illustrating a remote control method of the work machine according to the embodiment.

FIG. 12 is a block diagram illustrating a computer system according to the embodiment.

FIG. 13 is a diagram illustrating an operation of the work machine according to the embodiment.

FIG. 14 is a flowchart illustrating the remote control method of the work machine according to the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited thereto. Components of the embodiments described below can be appropriately combined. Further, some components may not be used.

In the embodiments, positional relationship of each part will be described using terms of “left”, “right”, “front”, “back”, “top”, and “bottom”. These terms indicate relative positions or directions with respect to a center of a swinging platform 3 of a work machine 1.

First Embodiment Remote Control System

FIG. 1 is a schematic diagram illustrating a remote control system 100 of the work machine 1 according to an embodiment. The remote control system 100 performs remote control of the work machine 1 operating at a work site. An example of the work site is a mine or a quarry.

At least a part of the remote control system 100 is disposed in a remote control room 200. The remote control room 200 is installed in a remote place away from the work site. The remote control system 100 includes a remote controller 40, a display apparatus 50, and a control apparatus 60.

The remote controller 40 is disposed in the remote control room 200. The remote controller 40 is operated by an operator in the remote control room 200. The operator can operate the remote controller 40 in a state seated on an operating seat 45.

The display apparatus 50 is disposed in the remote control room 200. The display apparatus 50 displays an image of the work site. The operator in the remote control room 200 cannot directly visually recognize a situation in the work site. The operator in the remote control room 200 can visually recognize the situation in the work site via the display apparatus 50.

The operator operates the remote controller 40 while viewing the image of the work site displayed on the display apparatus 50. The work machine 1 is remotely controlled by the remote controller 40.

The control apparatus 60 is disposed in the remote control room 200. The control apparatus 60 includes a computer system.

The work machine 1 is provided with a control apparatus 300. The control apparatus 300 includes a computer system.

The control apparatus 60 and the control apparatus 300 communicate with each other via a communication system 400. Examples of the communication system 400 include the Internet, a local area network (LAN), a mobile phone communication network, and a satellite communication network. The communication system 400 may include a relay station that relays data to be communicated.

Work Machine

FIG. 2 is a perspective view illustrating the work machine 1 according to the embodiment. FIG. 3 is a side view illustrating the work machine 1 according to the embodiment. In the embodiment, it is assumed that the work machine 1 is an excavator that is one type of loading machine. The work machine 1 operates at the work site. The work machine 1 operates, for example, in a loading area of the work site. The work machine 1 performs excavation of a work target. Examples of the work target include earth and sand or ore. In addition, a dump truck, which is one type of a haulage vehicle, operates at the work site. The work machine 1 performs loading work to load a cargo onto the dump truck. As the cargo, an excavated object excavated by excavation is exemplified.

As illustrated in FIGS. 2 and 3 , the work machine 1 includes a traveling body 2, a swinging platform 3 supported by the traveling body 2, working equipment 4 mounted on the swinging platform 3, a hydraulic cylinder 5 that drives the working equipment 4, a position sensor 71 that detects a position of the work machine 1, a vehicle attitude sensor 72 that detects an attitude of the swinging platform 3, a working equipment attitude sensor 73 that detects an attitude of the working equipment 4, and an imaging apparatus 30.

The traveling body 2 travels in a state of supporting the swinging platform 3. The swinging platform 3 is a vehicle body of the work machine 1. Traveling body 2 is disposed below the swinging platform 3. The traveling body 2 rotatably supports the swinging platform 3. The traveling body 2 includes a drive wheel 2A, a driven wheel 2B, and a crawler 2C supported by the drive wheel 2A and the driven wheel 2B. Each of the drive wheel 2A and the driven wheel 2B rotates about a rotation axis DX. A pair of drive wheels 2A, a pair of driven wheels 2B, and a pair of crawlers 2C are provided. The crawler 2C is rotated by the rotation of the drive wheel 2A. When the crawler 2C rotates, the traveling body 2 travels.

The swinging platform 3 can swing about a swing axis RX in the state of being supported by the traveling body 2. The swing axis RX extends in a top-bottom direction. The swinging platform 3 includes a cab 3A, a lower deck 3B, a step 3C, and an upper deck 3D. The cab 3A is an internal space of the swinging platform 3 where an operator can board. The cab 3A is disposed at a front and upper part of the swinging platform 3. The lower deck 3B is disposed at a back and lower part of the swinging platform 3. The upper deck 3D is disposed at the front and upper part of the swinging platform 3. Step 3C connects the lower deck 3B and the upper deck 3D. The upper deck 3D is disposed around the cab 3A. At least a part of the upper deck 3D is disposed in front of the cab 3A. A fence-like handrail 3E is arranged in each of the lower deck 3B, the step 3C, and the upper deck 3D.

Each of the lower deck 3B, the step 3C, and the upper deck 3D includes a passage through which the operator can pass. The operator can board the cab 3A by passing the lower deck 3B, the step 3C, and the upper deck 3D.

The swinging platform 3 includes a ladder 3F. The ladder 3F is connected to the upper deck 3D.

The working equipment 4 is mounted on the front part of the swinging platform 3. The working equipment 4 is disposed in front of the swing axis RX. The working equipment 4 is operable to extend forward. The working equipment 4 includes a boom 4A connected to the swinging platform 3, an arm 4B connected to the boom 4A, and a bucket 4C connected to the arm 4B. A proximal end part of the boom 4A is connected to the front part of the swinging platform 3 via a pin. The proximal end part of the arm 4B is connected to a distal end part of the boom 4A via a pin. A proximal end part of the bucket 4C is connected to a distal end part of the arm 4B via a pin. The bucket 4C has a tip blade 4D. The bucket 4C excavates the work target.

The boom 4A is connected to the front part of the swinging platform 3 so as to be rotatable about a boom rotation axis AX. The arm 4B is connected to the boom 4A so as to be rotatable about an arm rotation axis BX. The bucket 4C is connected to the arm 4B so as to be rotatable about a bucket rotation axis CX.

The boom rotation axis AX, the arm rotation axis BX, and the bucket rotation axis CX are parallel. Each of the boom rotation axis AX, the arm rotation axis BX, and the bucket rotation axis CX extends in a vehicle width direction of the swinging platform 3.

In the embodiment, the work machine 1 is a loading excavator. The loading excavator is an excavator in which the bucket 4C is attached to the arm 4B such that the tip blade 4D of the bucket 4C faces forward.

The hydraulic cylinder 5 includes a boom cylinder 5A that drives the boom 4A, an arm cylinder 5B that drives the arm 4B, and a bucket cylinder 5C that drives the bucket 4C. A proximal end part of the boom cylinder 5A is connected to the swinging platform 3. A distal end part of the boom cylinder 5A is connected to the boom 4A. A proximal end part of the arm cylinder 5B is connected to the boom 4A. A distal end part of the arm cylinder 5B is connected to the arm 4B. A proximal end part of the bucket cylinder 5C is connected to the boom 4A. A distal end part of the bucket cylinder 5C is connected to the bucket 4C.

The position sensor 71 detects the position of the work machine 1. The position sensor 71 detects an absolute position of the work machine 1 using a global navigation satellite system (GNSS). The position sensor 71 includes a GNSS receiver provided in the swinging platform 3.

The vehicle attitude sensor 72 detects the attitude of the swinging platform 3. The attitude of the swinging platform 3 includes an inclination angle (roll, pitch) of the swinging platform 3 with respect to a horizontal plane. The vehicle attitude sensor 72 includes an inertial measurement unit (IMU) provided in the swinging platform 3.

The working equipment attitude sensor 73 detects the attitude of the working equipment 4. The attitude of the working equipment 4 includes an angle of the working equipment 4. The working equipment attitude sensor 73 includes a boom attitude sensor 73A that detects an angle of the boom 4A with respect to the swinging platform 3, an arm attitude sensor 73B that detects an angle of the arm 4B with respect to the boom 4A, and a bucket attitude sensor 73C that detects an angle of the bucket 4C with respect to the arm 4B.

In the embodiment, the working equipment attitude sensor 73 is a stroke sensor disposed in the hydraulic cylinder 5. The hydraulic cylinder 5 includes a cylinder tube, a piston that moves inside the cylinder tube, and a rod connected to the piston. The stroke sensor detects a stroke length of the hydraulic cylinder 5 indicating a movement distance of the rod. The stroke length refers to a movement distance of the rod from the stroke end of the hydraulic cylinder 5. The stroke end refers to an end position in a movable range of the rod. In other words, the stroke end refers to a position of the rod in a state that the hydraulic cylinder 5 is most contracted or a position of the rod in a state that the hydraulic cylinder 5 is most extended.

The boom attitude sensor 73A is a stroke sensor disposed in the boom cylinder 5A. The boom attitude sensor 73A detects a stroke length of the boom cylinder 5A.

The arm attitude sensor 73B is a stroke sensor disposed in the arm cylinder 5B. The arm attitude sensor 73B detects a stroke length of the arm cylinder 5B.

The bucket attitude sensor 73C is a stroke sensor disposed in the bucket cylinder 5C. The bucket attitude sensor 73C detects a stroke length of the bucket cylinder 5C.

The imaging apparatus 30 captures the work site to acquire an image of the work site. The imaging apparatus 30 is disposed in the swinging platform 3. The imaging apparatus 30 is fixed to the swinging platform 3.

Examples of the image of the work site acquired by the imaging apparatus 30 include an image of the work target of the work machine 1, an image of at least a part of the work machine 1, an image of a structure existing at the work site, an image of a work machine different from the work machine 1, and an image of a worker working at the work site. In the embodiment, the image of the work target of the work machine 1 includes an image of an excavation target of the working equipment 4.

The imaging apparatus 30 includes an optical system and an image sensor that receives light passing through the optical system. The image sensor includes a couple charged device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor.

In the embodiment, the imaging apparatus 30 captures an image in an imaging range M. The imaging range M is set to include the work target of the work machine 1.

In the embodiment, the top-bottom direction is a direction parallel to the swing axis RX. A left-right direction is a direction parallel to the boom rotation axis AX. A front-back direction is a direction orthogonal to both the boom rotation axis AX and the swing axis RX. A direction in which the swinging platform 3 exists with reference to a ground contact surface of the traveling body 2 is toward top, and a direction opposite to the top is bottom. One of the left and right directions with reference to the swing axis RX is right, and a direction opposite to the right is left. A direction in which the working equipment 4 exists with reference to the swing axis RX is front, and a direction opposite to the front is back.

In the embodiment, the imaging apparatus 30 is disposed in the cab 3A. An optical axis OA of the optical system of the imaging apparatus 30 extends in the front-back direction.

In the following description, an image in the imaging range M captured by the imaging apparatus 30 is referred to as an image P as appropriate.

Remote Control Room

FIG. 4 is a diagram illustrating the remote control room 200 according to the embodiment. As illustrated in FIG. 4 , the remote controller 40 and the display apparatus 50 are disposed in the remote control room 200.

The remote controller 40 is operated by the operator seated on the operating seat 45. The operator sits on the operating seat 45 so as to face a display screen of the display apparatus 50. The operator operates the remote controller 40 while viewing the display screen of the display apparatus 50.

An operation signal generated by operating the remote controller 40 is transmitted to the control apparatus 300 of the work machine 1 via the control apparatus 60 and the communication system 400. The control apparatus 300 operates the work machine 1 according to the operation signal acquired via the communication system 400. The work machine 1 is operated by the operation signal from the remote place of the work machine 1. An operation of the work machine 1 includes at least one of an operation of the traveling body 2, an operation of the swinging platform 3, and an operation of the working equipment 4.

The operation of the traveling body 2 includes a forward operation and a backward operation of the traveling body 2. The operation of the swinging platform 3 includes a left swing operation and a right swing operation of the swinging platform 3. The operation of the working equipment 4 includes an elevating operation of the boom 4A, a lowering operation of the boom 4A, a dumping operation of the arm 4B, an excavating operation of the arm 4B, an excavating operation of the bucket 4C, and a dumping operation of the bucket 4C.

The remote controller 40 includes a left working lever 41 and a right working lever 42 operated for the operation of the swinging platform 3 and the working equipment 4, and a left travel pedal 43 and a right travel pedal 44 operated for the operation of the traveling body 2.

The left working lever 41 is disposed on a left side of the operating seat 45. The right working lever 42 is disposed on a right side of the operating seat 45. As an example, when the left working lever 41 is operated in the front-back direction, the arm 4B performs the dumping operation or the excavating operation. When the left working lever 41 is operated in the left-right direction, the swinging platform 3 performs the left swing operation or the right swing operation. When the right working lever 42 is operated in the left-right direction, the bucket 4C performs the excavating operation or the dumping operation. When the right working lever 42 is operated in the front-back direction, the boom 4A performs the lowering operation or the elevating operation. Note that when the left working lever 41 is operated in the front-back direction, the swinging platform 3 may perform the right swing operation or the left swing operation, and when the left working lever 41 is operated in the left-right direction, the arm 4B may perform the dumping operation or the excavating operation. The operating direction of the left working lever 41 and the operating direction of the right working lever 42 are arbitrarily related to the operation of the working equipment 4.

The left travel pedal 43 and the right travel pedal 44 are disposed on a front lower part of the operating seat 45. The left travel pedal 43 is disposed to the left of the right travel pedal 44. When the left travel pedal 43 is operated, the crawler 2C on the left side of the traveling body 2 moves forward or backward. When the right travel pedal 44 is operated, the crawler 2C on the right side of the traveling body 2 moves forward or backward.

In the remote control room 200, a first monitor device 501 that displays work machine operation data indicating an operation status of the work machine 1 and an operation switch 502 that is operated to activate an electric apparatus equipped in the work machine 1 are disposed. The first monitor device 501 displays, for example, a remaining amount of fuel of an engine mounted on the work machine 1, a temperature of coolant of the engine, a temperature of hydraulic oil for driving the hydraulic cylinder 5, and a traveling speed of the traveling body 2 as the work machine operation data. The operation switch 502 operates, for example, a headlight provided in the work machine 1 as the electric apparatus equipped in the work machine 1.

The display apparatus 50 displays the image P transmitted from the work machine 1. The image P is transmitted to the control apparatus 60 of the remote control system 100 via the control apparatus 300 and the communication system 400. The control apparatus 60 causes the display apparatus 50 to display the image P acquired via the communication system 400.

The display apparatus 50 includes a flat panel display such as a liquid crystal display (LCD) or an organic electroluminescence display (OELD). In the embodiment, the display apparatus 50 includes a plurality of flat panel displays arranged adjacent to each other. In the embodiment, the display apparatus 50 includes a central display 51, a left display 52 disposed on a left side of the central display 51, a right display 53 disposed on a right side of the central display 51, an upper display 54 disposed above the central display 51, and a lower display 55 disposed below the central display 51.

The image P displayed on the display apparatus 50 is an image corresponding to a field of view of a front space of the operator when the operator is assumed to be seated on a driver seat provided in the cab 3A of the work machine 1. The operator in the remote control room 200 can obtain a feeling of actually sitting on the driver's seat of the work machine 1.

The operator in the remote control room 200 operates the remote controller 40 to operate the working equipment 4 and excavate the work target. The excavated object excavated by the bucket 4C of the working equipment 4 is loaded onto the dump truck as a cargo.

In the embodiment, the dump truck is an unmanned dump truck that travels according to a control command transmitted from a control facility in the work site. In the remote control room 200, a second monitor device 503 is arranged to display dump truck operation data indicating an operation status of the unmanned dump truck at the work site. In the unmanned dump truck, a position sensor is disposed to detect position data of the unmanned dump truck. The position sensor detects an absolute position of the unmanned dump truck using the global navigation satellite system (GNSS). The second monitor device 503 displays a position of each of the plurality of unmanned dump trucks operating at the work site as the dump truck operation data. In addition, the operator can stop or start the unmanned dump truck by operating an input unit provided in the second monitor device 503.

In the remote control room 200, a third monitor device 504 is disposed to display guidance data of the working equipment 4. As the guidance data, a relative distance between a target design surface of the work target and the working equipment 4, a shape of the work target, and an ore distribution of the work target are exemplified.

Hydraulic System

FIG. 5 is a schematic diagram illustrating a hydraulic system 20 of the work machine 1 according to the embodiment. As illustrated in FIG. 5 , the hydraulic system 20 includes a hydraulic pump 21, the hydraulic cylinder 5 that drives the working equipment 4 according to the hydraulic oil supplied from the hydraulic pump 21, a pump flow path 22 connected to the hydraulic pump 21, a flow rate control valve 23 that adjusts the flow rate of the hydraulic oil supplied to the hydraulic cylinder 5 via the pump flow path 22, and a pressure sensor 74 that detects a pressure of the hydraulic oil in the hydraulic cylinder 5.

The hydraulic pump 21 is driven by power transmitted from a power source of the work machine 1. As the power source of the work machine 1, a diesel engine or an electric motor is exemplified. The hydraulic pump 21 discharges the hydraulic oil. In the embodiment, the hydraulic pump 21 is a variable displacement hydraulic pump.

The hydraulic cylinder 5 operates the working equipment 4 according to the hydraulic oil supplied from the hydraulic pump 21. The working equipment 4 operates within a predetermined movable range. The hydraulic cylinder 5 includes the boom cylinder 5A that operates the boom 4A, the arm cylinder 5B that operates the arm 4B, and the bucket cylinder 5C that operates the bucket 4C.

The hydraulic cylinder 5 includes a bottom chamber BR and a rod chamber RR. When the hydraulic oil is supplied to the bottom chamber BR, the hydraulic cylinder 5 extends. When the hydraulic oil is supplied to the rod chamber RR, the hydraulic cylinder 5 contracts.

The flow rate control valve 23 adjusts the flow rate of the hydraulic oil supplied to the hydraulic cylinder 5. The flow rate control valve 23 includes a boom flow rate control valve 23A that adjusts the flow rate of the hydraulic oil supplied to the boom cylinder 5A, an arm flow rate control valve 23B that adjusts the flow rate of the hydraulic oil supplied to the arm cylinder 5B, and a bucket flow rate control valve 23C that adjusts the flow rate of the hydraulic oil supplied to the bucket cylinder 5C.

The flow rate control valve 23 includes a pump port Pa, a bottom port Pb, a rod port Pc, and a tank port Pd.

The pump port Pa is connected to the hydraulic pump 21 via a supply flow path 24 and the pump flow path 22. The bottom port Pb is connected to the bottom chamber BR of the hydraulic cylinder 5 via a bottom flow path 25. The rod port Pc is connected to the rod chamber RR of the hydraulic cylinder 5 via a rod flow path 26. The tank port Pd is connected to a tank 28 via a discharge flow path 27.

The hydraulic oil discharged from the hydraulic pump 21 can flow through the pump flow path 22 and the supply flow path 24 and then flow into the flow rate control valve 23 from the pump port Pa. The hydraulic oil flowing out from the bottom port Pb can flow into the bottom chamber BR of the hydraulic cylinder 5 after flowing through the bottom flow path 25. The hydraulic oil flowing out from the bottom chamber BR of the hydraulic cylinder 5 can flow through the bottom flow path 25 and then flow into the flow rate control valve 23 from the bottom port Pb. The hydraulic oil flowing out from the rod port Pc can flow into the rod chamber RR of the hydraulic cylinder 5 after flowing through the rod flow path 26. The hydraulic oil flowing out from the rod chamber RR of the hydraulic cylinder 5 can flow through the rod flow path 26 and then flow into the flow rate control valve 23 from the rod port Pc. The hydraulic oil flowing out from the tank port Pd flows through the discharge flow path 27 and then is discharged to the tank 28.

The flow rate control valve 23 is a slide spool type flow rate control valve that switches the flow rate and direction of the hydraulic oil supplied to the hydraulic cylinder 5 by moving a rod-shaped spool. When the spool moves in an axial direction, the supply of the hydraulic oil to the bottom chamber BR and the supply of the hydraulic oil to the rod chamber RR are switched. In addition, the flow rate of the hydraulic oil supplied to the hydraulic cylinder 5 is adjusted according to a movement amount of the spool.

The spool of the flow rate control valve 23 moves to a first operating position Q1 at which the hydraulic oil is supplied to the bottom chamber BR of the hydraulic cylinder 5, a second operating position Q2 at which the hydraulic oil is supplied to the rod chamber RR of the hydraulic cylinder 5, and a stop position Q3 arranged between the first operating position Q1 and the second operating position Q2 and at which the hydraulic oil does not flow.

When the spool of the flow rate control valve 23 is arranged at the first operating position Q1, the hydraulic oil discharged from the hydraulic pump 21 flows through the pump flow path 22 and the supply flow path 24, then flows into the flow rate control valve 23 from the pump port Pa, and flows out from the bottom port Pb. The hydraulic oil flowing out from the bottom port Pb flows through the bottom flow path 25 and then flows into the bottom chamber BR of the hydraulic cylinder 5. As a result, the hydraulic cylinder 5 extends. When the hydraulic cylinder 5 extends, the hydraulic oil flows out from the rod chamber BR. The hydraulic oil flowing out from the rod chamber BR of the hydraulic cylinder 5 flows through the rod flow path 26, then flows into the flow rate control valve 23 from the rod port Pc, and flows out from the tank port Pd. The hydraulic oil flowing out from the tank port Pd is discharged to the tank 28 via the discharge flow path 27.

When the spool of the flow rate control valve 23 is arranged at the second operating position Q2, the hydraulic oil discharged from the hydraulic pump 21 flows through the pump flow path 22 and the supply flow path 24, then flows into the flow rate control valve 23 from the pump port Pa, and flows out from the rod port Pc. The hydraulic oil flowing out from the rod port Pc flows through the rod flow path 26 and then flows into the rod chamber RR of the hydraulic cylinder 5. As a result, the hydraulic cylinder 5 contracts. When the hydraulic cylinder 5 contracts, the hydraulic oil flows out from the bottom chamber BR. The hydraulic oil flowing out from the bottom chamber BR of the hydraulic cylinder 5 flows through the bottom flow path 25, then flows into the flow rate control valve 23 from the bottom port Pb, and flows out from the tank port Pd. The hydraulic oil flowing out from the tank port Pd is discharged to the tank 28 via the discharge flow path 27.

When the spool of the flow rate control valve 23 is arranged at the stop position Q3, the hydraulic oil cannot flow through the flow rate control valve 23. The hydraulic cylinder 5 does not extend or contract.

The pressure sensor 74 detects the pressure of the hydraulic oil in the hydraulic cylinder 5. The pressure sensor 74 includes a boom pressure sensor 74A that detects the pressure of the hydraulic oil in the boom cylinder 5A, an arm pressure sensor 74B that detects the pressure of the hydraulic oil in the arm cylinder 5B, and a bucket pressure sensor 74C that detects the pressure of the hydraulic oil in the bucket cylinder 5C.

In the embodiment, the pressure sensor 74 detects the pressure of the hydraulic oil supplied to the hydraulic cylinder 5. The pressure sensor 74 is provided in each of the bottom flow path 25 and the rod flow path 26. When the hydraulic oil is supplied to the rod chamber RR and the hydraulic cylinder 5 contracts, the pressure sensor 74 provided in the rod flow path 26 detects the pressure of the hydraulic oil supplied to the hydraulic cylinder 5. When the hydraulic oil is supplied to the bottom chamber BR and the hydraulic cylinder 5 extends, the pressure sensor 74 provided in the bottom flow path 25 detects the pressure of the hydraulic oil supplied to the hydraulic cylinder 5. The pressure sensor 74 may be provided in each of the bottom chamber BR and the rod chamber RR.

Control Apparatus

FIG. 6 is a functional block diagram illustrating the remote control system 100 of the work machine 1 according to the embodiment. As illustrated in FIG. 6 , the remote control system 100 includes a communication device 6 disposed in a remote place, the control apparatus 60 connected to the communication device 6, the remote controller 40 connected to the control apparatus 60, and the display apparatus 50 connected to the control apparatus 60. In addition, the remote control system 100 includes a communication device 7 disposed in the work machine 1, the control apparatus 300 connected to the communication device 7, the imaging apparatus 30 connected to the control apparatus 300, a sensor 70 connected to the control apparatus 300, the traveling body 2 controlled by the control apparatus 300, the swinging platform 3 controlled by the control apparatus 300, and the hydraulic cylinder 5 controlled by the control apparatus 300. The sensor 70 includes the position sensor 71, the vehicle attitude sensor 72, the working equipment attitude sensor 73, and the pressure sensor 74.

The control apparatus 300 includes a traveling body control unit 301, a swinging platform control unit 302, a working equipment control unit 303, a stroke end determination unit 304, an image data transmission unit 305, and a sensor data transmission unit 306.

The traveling body control unit 301 receives an operation signal of the remote controller 40 transmitted from the control apparatus 60. The traveling body control unit 301 outputs a control signal for controlling the operation of the traveling body 2 according to the operation signal of the remote controller 40.

The swinging platform control unit 302 receives the operation signal of the remote controller 40 transmitted from the control apparatus 60. The swinging platform control unit 302 outputs a control signal for controlling the operation of the swinging platform 3 according to the operation signal of the remote controller 40.

The working equipment control unit 303 receives the operation signal of the remote controller 40 transmitted from the control apparatus 60. The working equipment control unit 303 outputs a control signal for controlling the operation of the working equipment 4 according to the operation signal of the remote controller 40. The control signal for controlling the operation of the working equipment 4 includes a control signal for controlling the operation of the hydraulic cylinder 5. The control signal for controlling the operation of the hydraulic cylinder 5 includes a control signal for controlling the flow rate control valve 23.

The stroke end determination unit 304 calculates an angle of the working equipment 4 based on detection data of the working equipment attitude sensor 73. The angle of the working equipment 4 and the stroke length of the hydraulic cylinder 5 are correlated. The stroke end determination unit 304 can calculate the angle of the working equipment 4 by performing arithmetic processing based on the detection data of the working equipment attitude sensor 73. The stroke end determination unit 304 can calculate the angle of the boom 4A with respect to the swinging platform 3 by performing arithmetic processing based on detection data of the boom attitude sensor 73A. The stroke end determination unit 304 can calculate the angle of the arm 4B with respect to the boom 4A by performing arithmetic processing based on detection data of the arm attitude sensor 73B. The stroke end determination unit 304 can calculate an angle of the bucket 4C with respect to the arm 4B by performing arithmetic processing based on detection data of the bucket attitude sensor 73C.

Further, the stroke end determination unit 304 can calculate a cylinder position of the hydraulic cylinder 5 based on the detection data of the working equipment attitude sensor 73. The cylinder position refers to a relative position of the rod with respect to the stroke end of the hydraulic cylinder 5. As described above, the stroke end refers to an end position of the rod in the movable range. The stroke end determination unit 304 can calculate a cylinder position of the boom cylinder 5A by performing arithmetic processing based on the detection data of the boom attitude sensor 73A. The stroke end determination unit 304 can calculate a cylinder position of the arm cylinder 5B by performing arithmetic processing based on the detection data of the arm attitude sensor 73B. The stroke end determination unit 304 can calculate a cylinder position of the bucket cylinder 5C by performing arithmetic processing based on the detection data of the bucket attitude sensor 73C.

In addition, the stroke end determination unit 304 can calculate the stroke length of the hydraulic cylinder 5 based on the detection data of the working equipment attitude sensor 73. As described above, the stroke length refers to the movement distance of the rod from the stroke end of the hydraulic cylinder 5.

In addition, the stroke end determination unit 304 can calculate a cylinder speed of the hydraulic cylinder 5 based on the detection data of the working equipment attitude sensor 73. The cylinder speed refers to a speed of the rod with respect to the cylinder tube of the hydraulic cylinder 5. The stroke end determination unit 304 can calculate a cylinder speed of the boom cylinder 5A by performing arithmetic processing based on the detection data of the boom attitude sensor 73A. The stroke end determination unit 304 can calculate a cylinder speed of the arm cylinder 5B by performing arithmetic processing based on the detection data of the arm attitude sensor 73B. The stroke end determination unit 304 can calculate a cylinder speed of the bucket cylinder 5C by performing arithmetic processing based on the detection data of the bucket attitude sensor 73C.

In other words, in the embodiment, the working equipment attitude sensor 73 can function as at least one of an angle sensor of the working equipment 4, a cylinder position sensor of the hydraulic cylinder 5, a stroke length sensor of the hydraulic cylinder 5, and a cylinder speed sensor of the hydraulic cylinder 5.

Note that the working equipment attitude sensor 73 may include an angle sensor capable of detecting the angle of the working equipment 4 such as a potentiometer. Still more, the working equipment attitude sensor 73 may be an inertial measurement unit (IMU) provided in the working equipment 4.

The stroke end determination unit 304 determines whether the working equipment 4 approaches the end position in the movable range based on the detection data of the working equipment attitude sensor 73.

FIG. 7 is a schematic diagram illustrating the movable range of the working equipment 4 according to the embodiment. The working equipment 4 includes a plurality of working equipment components that can be relatively moved. The working equipment components of the working equipment 4 include the boom 4A, the arm 4B, and the bucket 4C. In the following description, the movable range of the working equipment 4 is the movable range of the working equipment components.

The working equipment 4 can move within the movable range determined by the stroke of the hydraulic cylinder 5. The movable range of the working equipment 4 is determined based on the movable range of the rod of the hydraulic cylinder 5. The end position in the movable range of the working equipment 4 is defined based on the stroke end of the hydraulic cylinder 5. When the hydraulic cylinder 5 reaches the stroke end, the working equipment 4 reaches the end position in the movable range.

In the embodiment, an end zone, an alarm zone, and an intermediate zone are defined in the movable range of the working equipment 4. The end zone is a part of the movable range including the end position. The intermediate zone is a part of the movable range including a central position of the movable range. The alarm zone is a part of the movable range between the end zone and the central position. In the embodiment, the alarm zone is a section between the end zone and the intermediate zone. The alarm zone is defined so as to be adjacent to each of the end zone and the intermediate zone. As described later, when the working equipment 4 approaches the end position in the alarm zone, an alarm is output in the remote place.

The alarm zone may be included in the end zone. The alarm zone may be omitted.

A ratio of a length of the end zone to the movable range can be arbitrarily set. The end zone may have an arbitrary ratio from 1 [%] to 20 [%], inclusive, of the movable range. Similarly, a ratio of a length of the alarm zone to the movable range can be arbitrarily set. The alarm zone may be an arbitrary ratio from 1 [%] to 20 [%], inclusive, of the movable range. The length of the end zone is shorter than the length of the intermediate zone.

The stroke end determination unit 304 determines whether the working equipment 4 exists in the end zone including the end position in the movable range based on the detection data of the working equipment attitude sensor 73. The end position in the movable range of the working equipment 4 is defined based on the stroke end of the hydraulic cylinder 5. The end zone of the movable range of the working equipment 4 is defined based on the stroke length of the hydraulic cylinder 5. The stroke end determination unit 304 can determine whether the working equipment 4 exists in the end zone of the movable range based on the detection data of the working equipment attitude sensor 73.

Similarly, the stroke end determination unit 304 can determine whether or not the working equipment 4 exists in the alarm zone between the end zone and the central position of the movable range based on the detection data of the working equipment attitude sensor 73. The stroke end determination unit 304 can determine whether the working equipment 4 exists in the intermediate zone including the central position of the movable range based on the detection data of the working equipment attitude sensor 73.

In the embodiment, the working equipment control unit 303 performs cushion control. The cushion control is control to decelerate the rod when the rod of the hydraulic cylinder 5 approaches the stroke end. In the cushion control, the working equipment control unit 303 decelerates the rod more than the cylinder speed set based on the operation signal generated by the remote controller 40. In the cushion control, the speed of the rod decreases as a distance between the rod of the hydraulic cylinder 5 and the stroke end decreases. The cushion control reduces impact when the rod of the hydraulic cylinder 5 reaches the stroke end.

When the stroke end determination unit 304 determines that the working equipment 4 is close to the end position in the movable range, the working equipment control unit 303 outputs, to the flow rate control valve 23, a control command for reducing the flow rate of the hydraulic oil supplied to the hydraulic cylinder 5. As a result, the cushion control to reduce the speed of the working equipment 4 approaching the end position is performed. In the cushion control, the speed of the working equipment 4 decreases as the distance between the working equipment 4 and the end position decreases. The speed of the working equipment 4 may be gradually reduced as the distance between the working equipment 4 and the end position becomes shorter, or may be reduced stepwise. In the cushion control, when the working equipment 4 reaches the end position, the speed of the working equipment 4 may or may not be zero.

In the embodiment, the cushion control is performed when the working equipment 4 is arranged in the end zone and the working equipment 4 is operated to approach the end position. In other words, when the stroke end determination unit 304 determines that the working equipment 4 approaches the end position in the end zone, the working equipment control unit 303 outputs, to the flow rate control valve 23, the control command for reducing the flow rate of the hydraulic oil supplied to the hydraulic cylinder 5. Accordingly, when the working equipment 4 approaches the end position in the end zone, the cushion control for reducing the speed of the working equipment 4 is performed.

For example, when the stroke end determination unit 304 determines that the boom 4A is operated to approach the end position in the end zone of the movable range, the working equipment control unit 303 outputs, to the boom flow rate control valve 23A, a control command for reducing the flow rate of the hydraulic oil supplied to the boom cylinder 5A. When the stroke end determination unit 304 determines that the arm 4B is operated to approach the end position in the end zone of the movable range, the working equipment control unit 303 outputs, to the arm flow rate control valve 23B, a control command for reducing the flow rate of the hydraulic oil supplied to the arm cylinder 5B. When the stroke end determination unit 304 determines that the bucket 4C is operated to approach the end position in the end zone of the movable range, the working equipment control unit 303 outputs, to the bucket flow rate control valve 23C, a control command for reducing the flow rate of the hydraulic oil supplied to the bucket cylinder 5C.

The image data transmission unit 305 transmits an image around the work machine 1 acquired by the imaging apparatus 30 to the control apparatus 60. The image data transmission unit 305 acquires the image P in the imaging range M from the imaging apparatus 30. The image data transmission unit 305 transmits the image P to the control apparatus 60.

The sensor data transmission unit 306 transmits detection data of the sensor 70 mounted on the work machine 1 to the control apparatus 60. As described above, the sensor 70 includes the position sensor 71 that detects the position of the work machine 1, the vehicle attitude sensor 72 that detects the attitude of the swinging platform 3, the working equipment attitude sensor 73 that detects the attitude of the working equipment 4, and the pressure sensor 74 that detects the pressure of the hydraulic oil in the hydraulic cylinder 5.

The communication device 7 communicates with the communication device 6 via the communication system 400. The communication device 7 receives the operation signal of the remote controller 40 transmitted from the control apparatus 60 via the communication device 6, and outputs the operation signal to the control apparatus 300. The communication device 7 transmits the image P in the imaging range M received from the image data transmission unit 305 to the communication device 6 in the remote place. The communication device 7 includes an encoder that compresses image data of the image P. The image P is transmitted from the communication device 7 to the communication device 6 in a compressed state. The communication device 7 transmits the detection data of the position sensor 71, the detection data of the vehicle attitude sensor 72, the detection data of the working equipment attitude sensor 73, and the detection data of the pressure sensor 74 received from the sensor data transmission unit 306 to the communication device 6 in the remote place.

The communication device 6 communicates with the communication device 7 via the communication system 400. The communication device 6 transmits the operation signal generated by operating the remote controller 40 to the communication device 7. The communication device 6 receives the image P transmitted from the control apparatus 300 via the communication device 7, and outputs the image P to the control apparatus 60. The communication device 6 includes a decoder that restores the image data of the image P compressed. The image P is output from the communication device 6 to the control apparatus 60 in a restored state. The communication device 6 receives the detection data of the position sensor 71, the detection data of the vehicle attitude sensor 72, the detection data of the working equipment attitude sensor 73, and the detection data of the pressure sensor 74 transmitted from the control apparatus 300 via the communication device 7, and outputs them to the control apparatus 60.

The control apparatus 60 includes an operation signal transmission unit 61, an image data reception unit 62, a sensor data reception unit 63, an image processing unit 64, a display control unit 65, and an alarm control unit 66.

The operation signal transmission unit 61 transmits an operation signal for performing the remote control of the work machine 1. When the remote controller 40 is operated by the operator, the operation signal for performing the remote control of the work machine 1 is generated. The operation signal transmission unit 61 transmits the operation signal of the remote controller 40 to the control apparatus 300.

The image data reception unit 62 receives the image around the work machine 1. The image data reception unit 62 receives the image P as the image around the work machine 1. The image data reception unit 62 acquires the image P restored by the decoder of the communication device 6.

The sensor data reception unit 63 receives the detection data of the sensor 70. The detection data of the sensor 70 includes detection data related to the swinging platform 3 and detection data related to the working equipment 4. The sensor data reception unit 63 receives detection data of the position of the work machine 1 detected by the position sensor 71, detection data of the attitude of the swinging platform 3 detected by the vehicle attitude sensor 72, detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73, and detection data of the pressure of the hydraulic oil in the hydraulic cylinder 5 detected by the pressure sensor 74.

The image processing unit 64 divides the image P received by the image data reception unit 62.

FIG. 8 is a diagram illustrating a process by the image processing unit 64 according to the embodiment. As illustrated in FIG. 8 , the image P is acquired by the image data reception unit 62. The image P is an image of a front space SP of the swinging platform 3. A part of the working equipment 4 including the bucket 4C is captured in the image P. The work target in front of the swinging platform 3 is also captured in the image P. Still more, the handrail 3E of the upper deck 3D is captured in the image P.

The image processing unit 64 divides the image P into a plurality of images. The image processing unit 64 divides the image P into an image P11 to be displayed on the central display 51, an image P12 to be displayed on the left display 52, an image P13 to be displayed on the right display 53, an image P14 to be displayed on the upper display 54, and an image P15 to be displayed on the lower display 55.

The display control unit 65 causes the display apparatus 50 to display the image around the work machine 1. The display control unit 65 causes the display apparatus 50 to display the image P as the image around the work machine 1.

FIG. 9 is a diagram illustrating a process by the display control unit 65 according to the embodiment. As illustrated in FIG. 9 , the display control unit 65 causes the central display 51 to display the image P11 that is a part of the image P. The display control unit 65 causes the left display 52 to display the image P12 that is a part of the image P. The display control unit 65 causes the right display 53 to display the image P13 that is a part of the image P. The display control unit 65 causes the upper display 54 to display the image P14 that is a part of the image P. The display control unit 65 causes the lower display 55 to display the image P15 that is a part of image P.

In the embodiment, the display control unit 65 causes the display apparatus 50 to display a vehicle data image P3 indicating the attitude of the swinging platform 3, a working equipment data image P4 indicating the attitude of the working equipment 4, a load data image P5 indicating a weight of the cargo to be loaded onto the dump truck, and a bucket data image P6 indicating the position of the tip blade 4D of the bucket 4C.

The display control unit 65 calculates the inclination angle of the swinging platform 3 with respect to the horizontal plane based on the detection data of the vehicle attitude sensor 72. The display control unit 65 causes the display apparatus 50 to display a symbol image indicating the inclination angle of the swinging platform 3 as the vehicle data image P3. In the embodiment, the vehicle data image P3 is displayed on the upper display 54.

In addition, the display control unit 65 calculates the attitude of the working equipment 4 based on the detection data of the working equipment attitude sensor 73. The display control unit 65 causes the display apparatus 50 to display an animation image indicating the attitude of the working equipment 4 as the working equipment data image P4. In the embodiment, the working equipment data image P4 is displayed on the right display 53.

In addition, the display control unit 65 calculates the weight of the cargo to be loaded onto the dump truck based on the detection data of a weight sensor (not illustrated) that detects the weight of the cargo held by the bucket 4C. The display control unit 65 causes the display apparatus 50 to display an indicator image indicating the weight of the cargo as the load data image P5. In the embodiment, the load data image P5 is displayed on the right display 53. Note that the weight sensor that detects the weight of the cargo loaded on the dump truck may be provided on the dump truck, and detection data of the weight sensor may be transmitted to the control apparatus 60.

In addition, the display control unit 65 calculates the position of the tip blade 4D of the bucket 4C in the top-bottom direction based on the detection data of the working equipment attitude sensor 73. The display control unit 65 causes the display apparatus 50 to display an indicator image indicating the position in the top-bottom direction of the tip blade 4D of the bucket 4C as the bucket data image P6. The position in the top-bottom direction of the tip blade 4D is a height position from ground GR. In the embodiment, the bucket data image P6 is displayed on the right display 53.

The alarm control unit 66 outputs an alarm control signal when determining that the working equipment 4 approaches the end position in the movable range of the working equipment 4 based on the detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73. In other words, the alarm control unit 66 outputs the alarm control signal when determining that the piston of the hydraulic cylinder 5 approaches the stroke end and the working equipment 4 is approaching the end position in the movable range.

The alarm control unit 66 outputs the alarm control signal when determining that the working equipment 4 is operated to approach the end position in the alarm zone based on the detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73. In the embodiment, the alarm control unit 66 starts outputting the alarm control signal when determining that the working equipment 4 has moved from the intermediate zone to the alarm zone.

As described above, the cushion control starts when the working equipment 4 moves from the alarm zone to the end zone. In the embodiment, when determining that the working equipment 4 has moved from the intermediate zone to the alarm zone, the alarm control unit 66 starts outputting the alarm control signal before the cushion control starts.

The alarm control unit 66 outputs the alarm control signal when determining that the working equipment 4 is operated to approach the end position in the end zone based on the detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73. In the embodiment, the alarm control unit 66 continues to output the alarm control signal when determining that the working equipment 4 is moving toward the end position in each of the alarm zone and the end zone. When the stroke end determination unit 304 determines that the working equipment 4 has moved from the alarm zone to the end zone, the working equipment control unit 303 starts the cushion control.

In addition, the alarm control unit 66 outputs the alarm control signal when determining that the working equipment 4 has reached the end position based on the detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73. In other words, in the embodiment, the alarm control unit 66 outputs the alarm control signal when the working equipment 4 moves toward the end position in each of the alarm zone and the end zone, and when the working equipment 4 reaches the end position.

FIG. 10 is a diagram illustrating a process by the alarm control unit 66 according to the embodiment. In the embodiment, the alarm control unit 66 outputs the alarm control signal to the display apparatus 50. The display apparatus 50 is provided in the remote place from the work machine 1, and outputs an alarm based on the alarm control signal from the alarm control unit 66. In the embodiment, the display apparatus 50 functions as an alarm device. As illustrated in FIG. 10 , when the hydraulic cylinder 5 approaches the stroke end and the working equipment 4 is operated to approach the end position, the alarm control unit 66 blinks the working equipment data image P4 as the alarm. The alarm control unit 66 may blink the entire working equipment data image P4 or may blink a background image of the working equipment data image P4. The alarm control unit 66 may change a color of the working equipment 4 displayed on the display apparatus 50 or blink the image of the working equipment 4 as the alarm. The color of the working equipment 4 may be changed by changing the color of the entire working equipment 4 or by changing the color of a part of the working equipment 4. For example, when the arm 4B is close to the end position, the alarm control unit 66 may change the color of the arm 4B. The blinking of the image of the working equipment 4 may be blinking of the entire image of the working equipment 4 or blinking of a part of the image of the working equipment 4. For example, when the arm 4B is close to the end position, the alarm control unit 66 may blink the image of the arm 4B.

Note that the alarm control unit 66 may cause the display apparatus 50 to display computer graphics (CG) as the alarm. For example, when the bucket 4C is close to the end position, the alarm control unit 66 may cause the display apparatus 50 to superimpose computer graphics indicating the position and attitude of the bucket 4C on the image P in the display.

Remote Control Method

FIG. 11 is a flowchart illustrating a remote control method of the work machine 1 according to the embodiment.

When the remote controller 40 is operated, the operation signal for performing the remote control of the work machine 1 is transmitted from the operation signal transmission unit 61 of the control apparatus 60 to the control apparatus 300 (Step SB1).

The imaging apparatus 30 captures an image in the imaging range M. The image data transmission unit 305 transmits the image P to the control apparatus 60 via the communication device 7 and the communication system 400 (Step SA1).

The working equipment attitude sensor 73 detects the attitude of the working equipment 4. The sensor data transmission unit 306 transmits the detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73 to the control apparatus 60 via the communication device 7 and the communication system 400 (Step SA2).

In the embodiment, the sensor data transmission unit 306 transmits not only the detection data of the working equipment attitude sensor 73 but also the detection data of the position sensor 71, the detection data of the vehicle attitude sensor 72, and the detection data of the pressure sensor 74 to the control apparatus 60 via the communication device 7 and the communication system 400.

Note that the process in Step SA2 may be performed before the process in Step SA1, or the process in Step SA1 and the process in Step SA2 may be performed in parallel.

The image data reception unit 62 receives the image P transmitted from the work machine 1 via the communication device 6.

The image processing unit 64 divides the image P into the image P11, the image P12, an image P13, the image P14, and the image P15 (Step SB2).

The display control unit 65 causes the display apparatus 50 to display the image P (Step SB3).

The stroke end determination unit 304 determines whether the working equipment 4 is approaching the end position in the end zone of the movable range based on the detection data of the working equipment attitude sensor 73 (Step SA3).

When it is determined in Step SA3 that the working equipment 4 is moving away from the end position in the end zone, or when it is determined that the working equipment 4 is not arranged in the end zone (Step SA3: No), the control apparatus 300 returns to the process in Step SA1.

When it is determined in Step SA3 that the working equipment 4 is operated to approach the end position in the end zone (Step SA3: Yes), the working equipment control unit 303 performs the cushion control (Step SA4).

More specifically, the working equipment control unit 303 outputs, to the flow rate control valve 23, the control command for reducing the flow rate of the hydraulic oil supplied to the hydraulic cylinder 5. As a result, the speed of the working equipment 4 operated to approach the end position in the end zone decreases.

The alarm control unit 66 determines whether the working equipment 4 is approaching the end position in the alarm zone of the movable range based on the detection data of the working equipment attitude sensor 73 (Step SB4).

In Step SB4, when it is determined that the working equipment 4 is moving away from the end position in the alarm zone, or when it is determined that the working equipment 4 is not arranged in each of the alarm zone and the end zone (Step SB4: No), the control apparatus 60 returns to the process in Step SB1.

In Step SB4, when it is determined that the working equipment 4 is operated to approach the end position in the alarm zone (Step SB4: Yes), the alarm control unit 66 outputs the alarm control signal (Step SB5).

Note that the determination in Step SA3 may be performed by the control apparatus 60 in the remote control room 200. The determination in Step SB4 may be performed by the control apparatus 300 of the work machine 1.

As described with reference to FIG. 10 , the alarm control unit 66 causes the display apparatus 50 to output the alarm. The operator in the remote place can recognize that the working equipment 4 is operated to approach the end position by looking at the alarm output from the display apparatus 50.

In the present embodiment, in order to simplify the description, the movable range of the working equipment 4 is determined based on the movable range of the rod of the hydraulic cylinder 5. In other words, the end position in the movable range of the working equipment 4 is defined based on the stroke end of the hydraulic cylinder 5, and when the hydraulic cylinder 5 reaches the stroke end, the working equipment 4 is determined to reach the end position in the movable range. However, based on relative angles of the working equipment components including the boom 4A, the arm 4B, and the bucket 4C, the working equipment components may reach the end position in the movable range, due to mechanical restriction of the working equipment 4, before the hydraulic cylinder 5 reaches the stroke end. In this case, the end positions of the working equipment components may be set based on a mechanical structure of the working equipment 4. Still more, the end zone and the alarm zone may be set based on the mechanical structure of the working equipment 4. For example, when a relative angle of a first working equipment component (e.g., boom 4A) and a second working equipment component (e.g., arm 4B) and a correlation of a third working equipment component (e.g., bucket 4C) with the end position (correlation data such as map data or a relational expression) are obtained in advance, the stroke end determination unit 304 can determine whether or not the third working equipment component is approaching the end position in the movable range based on the detection data of the working equipment attitude sensor 73 and the correlation obtained in advance.

Computer System

FIG. 12 is a block diagram illustrating a computer system 1000 according to the embodiment. Each of the control apparatus 60 and the control apparatus 300 described above includes the computer system 1000. The computer system 1000 includes a processor 1001 such as a central processing unit (CPU), a main memory 1002 including a nonvolatile memory such as a read only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 1003, and an interface 1004 including an input/output circuit. The function of the control apparatus 60 and the function of the control apparatus 300 described above are stored in the storage 1003 as a computer program. The processor 1001 reads the computer program from the storage 1003, develops the computer program in the main memory 1002, and executes the above-described processes according to the program. Note that the computer program may be distributed to the computer system 1000 via a network.

The computer program or the computer system 1000 arranged in the remote place can execute receiving the detection data of the attitude of the working equipment 4 and outputting the alarm control signal to the alarm device when determining that the working equipment 4 approaches or reaches the end position in the movable range based on the detection data according to the above-described embodiment.

Effects

As described above, according to the embodiment, the work machine 1 includes the communication device 6 that transmits the detection data of the working equipment attitude sensor 73 to the remote place. As a result, the operator in the remote place can recognize that an impact may act on the working equipment 4 based on the detection data of the working equipment attitude sensor 73.

For example, in a case where the cushion control is not performed, when the rod of the hydraulic cylinder 5 reaches the stroke end and the working equipment 4 reaches the end position in the movable range, the impact may act on the working equipment 4. When the operator actually boards the work machine 1, it is possible to feel that the impact acting on the working equipment 4. On the other hand, when the operator is in the remote place, it is not possible to feel the impact acting on the working equipment 4. Therefore, there is a possibility that the operator in the remote place further performs the remote control in which an excessive impact acts on the working equipment 4. When the excessive impact acts on the working equipment 4, deterioration of the working equipment 4 may be accelerated. In addition, even in a case where the cushion control is performed, when the working equipment 4 reaches the end position many times, the working equipment 4 may deteriorate.

In the embodiment, the detection data of the working equipment attitude sensor 73 is transmitted from the work machine 1 to the remote place. When it is determined that the working equipment 4 is operated to approach the end position in the movable range based on the detection data of the working equipment attitude sensor 73, the alarm is output in the remote place. As a result, the operator in the remote place can recognize that the working equipment 4 is approaching the end position. Therefore, the operator in the remote place can perform the remote control to avoid applying the excessive impact to the working equipment 4. For example, the operator in the remote place can operate the remote controller 40 such that the working equipment 4 does not reach the end position.

In the embodiment, the cushion control is performed when the working equipment 4 moves from the alarm zone to the end zone. As a result, the impact acting on the working equipment 4 is reduced. In addition, there is a possibility that the working equipment 4 reaches the end position against the intention of the operator in the remote place due to a communication delay of the image data acquired by the imaging apparatus 30. The possibility that the communication delay of image data acquired by the imaging apparatus 30 occurs is higher than a possibility that a communication delay of the operation signal of the remote controller 40 occurs. Even when the operator in the remote place operates the remote controller 40 to cause the working equipment 4 stop immediately before the end position, while viewing the image displayed on the display apparatus 50, there is a possibility that the working equipment 4 reaches the end position against the intention of the operator in the remote place due to the communication delay of the image data. According to the embodiment, the cushion control is performed based on the detection data of the working equipment attitude sensor 73. As a result, even when the communication delay of the image data occurs, an impact on the working equipment 4 is suppressed.

In the embodiment, when the working equipment 4 moves from the intermediate zone to the alarm zone, the alarm control unit 66 starts to output the alarm control signal, and the display apparatus 50 starts to output the alarm. In other words, the display apparatus 50 starts to output the alarm before the cushion control of the working equipment 4 is performed. As a result, the operator in the remote place can more reliably perform the remote control that does not cause the excessive impact to be applied to the working equipment 4.

Still more, even after the working equipment 4 moves from the alarm zone to the end zone, the alarm control unit 66 continues to output the alarm control signal, and thus the display apparatus 50 continues to output the alarm. As a result, the operator in the remote place can recognize that the working equipment 4 is approaching the end position in the end zone.

Furthermore, according to the embodiment, even after the working equipment 4 reaches the end position, the alarm control unit 66 continues to output the alarm control signal, and thus the display apparatus 50 continues to output the alarm. As a result, the operator in the remote place can recognize that the working equipment 4 has reached the end position.

Other Embodiments

In the embodiment described above, the stroke end determination unit 304 determines whether the working equipment 4 exists in the end zone of the movable range based on the detection data of the working equipment attitude sensor 73. The stroke end determination unit 304 may determine whether the working equipment 4 exists in the end zone of the movable range based on an output of a proximity switch. The proximity switch is a switch that operates when the working equipment 4 moves to the end position in the movable range.

Note that, in the above-described embodiment, the alarm control unit 66 causes the display apparatus 50 to output the alarm. For example, the alarm control unit 66 may cause at least a part of the first monitor device 501, the second monitor device 503, and the third monitor device 504 to output the alarm. In a case where the alarm is output by at least a part of the display apparatus 50, the first monitor device 501, the second monitor device 503, and the third monitor device 504, an alarm message such as “pay attention to lever operation” or “approaching stroke end” may be displayed. When a sound output device or a buzzer is arranged in the remote control room 200, the alarm control unit 66 may cause the sound output device or the buzzer to output an alarm sound as the alarm. When a vibration generator is disposed on the operating seat 45, the alarm control unit 66 may vibrate the operating seat 45 as the alarm. In other words, the alarm device may not be the display apparatus 50, and may be at least one of the first monitor device 501, the second monitor device 503, the third monitor device 504, the sound output device, the buzzer, and the vibration generator.

In the above-described embodiment, the alarm control unit 66 outputs the alarm before the working equipment 4 reaches the end position. However, the alarm control unit 66 may output the alarm when determining that the working equipment 4 has reached the end position in the movable range based on the detection data of the working equipment attitude sensor 73. In other words, the alarm control unit 66 may output the alarm after the working equipment 4 that is operated to approach the end position has reached the end position. As a result, the operator in the remote place can recognize, based on the alarm, that the working equipment 4 has reached the end position and that there is a possibility that an impact has acted on the working equipment 4. The computer program or the computer system 1000 arranged in the remote place described with reference to FIG. 12 can execute receiving the detection data of the attitude of the working equipment 4 and outputting the alarm when it is determined that the working equipment 4 has reached the end position in the movable range based on the detection data.

In the above embodiment, the output of the alarm may be omitted. The cushion control may be performed in a state that no alarm is output.

In the above-described embodiment, the cushion control may not be performed. For example, when the operator slowly operates the remote controller 40, the impact acting on the working equipment 4 is small. When the cylinder speed of the rod is equal to or lower than a speed threshold, the cushion control may not be performed.

Second Embodiment

A second embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference signs, and the description thereof is simplified or omitted.

FIG. 13 is a diagram illustrating the operation of the work machine 1 according to the embodiment. As illustrated in FIG. 13 , when the work machine 1 causes the working equipment 4 to collide with the work target, an impact may act on the working equipment 4. For example, there is a possibility that an impact acts on the working equipment 4 when the working equipment 4 excavates the work target or when the work machine 1 lowers the working equipment 4 to the work target. In addition, when the cushion control is not performed, there is a possibility that an impact acts on the working equipment 4 by the working equipment 4 reaching the end position.

In the embodiment, the alarm control unit 66 outputs the alarm control signal in a case where it is determined that a level of the impact acting on the working equipment 4 is equal to or greater than a threshold based on the detection data related to the working equipment 4 received by the sensor data reception unit 63. The threshold related to the level of impact is a predetermined value and is held in the alarm control unit 66.

When an impact acts on the working equipment 4, the working equipment 4 vibrates with an amplitude of a predetermined value or higher. In other words, when the impact acts on the working equipment 4, the attitude of the working equipment 4 changes such that the working equipment 4 reciprocates at the amplitude equal to or larger than a first threshold. The alarm control unit 66 can determine whether the level of the impact is equal to or greater than the threshold based on the detection data of the attitude of the working equipment 4 detected by the working equipment attitude sensor 73.

Still more, when an impact acts on the working equipment 4, a pressure of the hydraulic oil in the hydraulic cylinder 5 rapidly changes. More specifically, when the impact acts on the working equipment 4, the pressure of the hydraulic oil in the hydraulic cylinder 5 increases by a change amount equal to or greater than a second threshold. The alarm control unit 66 can determine whether the level of the impact is equal to or greater than the threshold based on the detection data of the pressure of the hydraulic oil detected by the pressure sensor 74.

Still more, when an impact acts on the working equipment 4, the swinging platform 3 vibrates in a pitch direction with an amplitude or acceleration equal to or greater than a predetermined value. The alarm control unit 66 can determine whether the level of the impact is equal to or greater than the threshold based on the detection data of the vehicle attitude sensor 72 including the inertial measurement unit (IMU) provided in the swinging platform 3.

Still more, when an impact acts on the working equipment 4, the working equipment 4 vibrates at an acceleration equal to or greater than a predetermined value. When the acceleration sensor is disposed in the working equipment 4, the alarm control unit 66 can determine whether the level of the impact is equal to or greater than the threshold based on the detection data of the acceleration sensor.

FIG. 14 is a flowchart illustrating a remote control method of the work machine 1 according to the embodiment. In an example illustrated in FIG. 14 , it is assumed that the alarm control unit 66 determines whether the level of the impact is equal to or greater than the threshold based on the detection data of the pressure of the hydraulic oil detected by the pressure sensor 74. As described above, the alarm control unit 66 can determine whether the level of the impact is equal to or greater than the threshold based on at least one of the detection data of the working equipment attitude sensor 73, the detection data of the vehicle attitude sensor 72, and the detection data of the acceleration sensor.

When the remote controller 40 is operated, the operation signal for performing the remote control of the work machine 1 is transmitted from the operation signal transmission unit 61 of the control apparatus 60 to the control apparatus 300 (Step SB11).

The image P is transmitted from the work machine 1 to the control apparatus 60 (Step SA11).

The detection data of the sensor 70 is transmitted from the work machine 1 to the control apparatus 60. In the embodiment, the sensor data transmission unit 306 transmits at least the detection data of the pressure of the hydraulic oil in the hydraulic cylinder 5 detected by the pressure sensor 74 to the control apparatus 60 via the communication device 7 and the communication system 400 (Step SA12).

Note that the process in Step SA12 may be performed before the process in Step SA11, or the process in Step SA11 and the process in Step SA12 may be performed in parallel.

The image data reception unit 62 receives the image P transmitted from the work machine 1 via the communication device 6. Image processing unit 64 divides the image P into the image P11, the image P12, the image P13, the image P14, and the image P15 (Step SB12).

The display control unit 65 causes the display apparatus 50 to display the image P (Step SB13).

The alarm control unit 66 determines whether the level of the impact acting on the working equipment 4 is equal to or greater than the threshold based on the detection data of the pressure sensor 74 (Step SB14).

In Step SB14, when it is determined that the level of the impact acting on the working equipment 4 is less than the threshold (Step SB14: No), the control apparatus 60 returns to the process in Step SB12.

In Step SB14, when it is determined that the level of the impact acting on the working equipment 4 is equal to or greater than the threshold value (Step SB14: Yes), the alarm control unit 66 outputs the alarm control signal (Step SB15).

Note that the determination in Step SB14 may be performed by the control apparatus 300 of the work machine 1.

As described above, the computer program or the computer system 1000 arranged in the remote place described with reference to FIG. 12 can execute receiving the detection data related to the working equipment 4 and outputting the alarm control signal to the alarm device in a case where it is determined that the level of the impact acting on the working equipment 4 is equal to or greater than the threshold based on the detection data.

Other Embodiments

In the above-described embodiment, the control apparatus 60 of the remote control room 200 functions as the alarm control unit 66. However, the control apparatus 300 of the work machine 1 may function as the alarm control unit 66. The alarm control signal output from the alarm control unit 66 provided in the work machine 1 may be transmitted to the remote control room 200 via the communication system 400, and the alarm device provided in the remote control room 200 may output the alarm based on the alarm control signal from the alarm control unit 66.

In the embodiment described above, the work machine 1 is a loading excavator. However, the work machine 1 may be a backhoe. Still more, the work machine 1 may be a bulldozer or a wheel loader as long as the work machine is equipped with the working equipment.

REFERENCE SIGNS LIST

-   1 WORK MACHINE -   2 TRAVELING BODY -   2A DRIVE WHEEL -   2B DRIVEN WHEEL -   2C CRAWLER -   3 SWINGING PLATFORM -   3A CAB -   3B LOWER DECK -   3C STEP -   3D UPPER DECK -   3E HANDRAIL -   3F LADDER -   4 WORKING EQUIPMENT -   4A BOOM -   4B ARM -   4C BUCKET -   4D TIP BLADE -   5 HYDRAULIC CYLINDER -   5A BOOM CYLINDER -   5B ARM CYLINDER -   5C BUCKET CYLINDER -   6 COMMUNICATION DEVICE -   7 COMMUNICATION DEVICE -   20 HYDRAULIC SYSTEM -   21 HYDRAULIC PUMP -   22 PUMP FLOW PATH -   23 FLOW CONTROL VALVE -   23A BOOM FLOW RATE CONTROL VALVE -   23B ARM FLOW RATE CONTROL VALVE -   23C BUCKET FLOW RATE CONTROL VALVE -   24 SUPPLY FLOW PATH -   25 BOTTOM FLOW PATH -   26 ROD FLOW PATH -   27 DISCHARGE FLOW PATH -   28 TANK -   30 IMAGING APPARATUS -   40 REMOTE CONTROLLER -   41 LEFT WORKING LEVER -   42 RIGHT WORKING LEVER -   43 LEFT TRAVEL PEDAL -   44 RIGHT TRAVEL PEDAL -   45 OPERATING SEAT -   50 DISPLAY APPARATUS -   51 CENTER DISPLAY -   52 LEFT DISPLAY -   53 RIGHT DISPLAY -   54 UPPER DISPLAY -   55 LOWER DISPLAY -   60 CONTROL APPARATUS -   61 OPERATION SIGNAL TRANSMISSION UNIT -   62 IMAGE DATA RECEPTION UNIT -   63 SENSOR DATA RECEPTION UNIT -   64 IMAGE PROCESSING UNIT -   65 DISPLAY CONTROL UNIT -   66 ALARM CONTROL UNIT -   70 SENSOR -   71 POSITION SENSOR -   72 VEHICLE ATTITUDE SENSOR -   73 WORKING EQUIPMENT ATTITUDE SENSOR -   73A BOOM ATTITUDE SENSOR -   73B ARM ATTITUDE SENSOR -   73C BUCKET ATTITUDE SENSOR -   74 PRESSURE SENSOR -   74A BOOM PRESSURE SENSOR -   74B ARM PRESSURE SENSOR -   74C BUCKET PRESSURE SENSOR -   100 REMOTE CONTROL SYSTEM -   200 REMOTE CONTROL ROOM -   300 CONTROL APPARATUS -   301 TRAVELING BODY CONTROL UNIT -   302 SWINGING PLATFORM CONTROL UNIT -   303 WORKING EQUIPMENT CONTROL UNIT -   304 STROKE END DETERMINATION UNIT -   305 IMAGE DATA TRANSMISSION UNIT -   306 SENSOR DATA TRANSMISSION UNIT -   400 COMMUNICATION SYSTEM -   501 FIRST MONITOR DEVICE -   502 OPERATION SWITCH -   503 SECOND MONITOR DEVICE -   504 THIRD MONITOR DEVICE -   1000 COMPUTER SYSTEM -   1001 PROCESSOR -   1002 MAIN MEMORY -   1003 STORAGE -   1004 INTERFACE -   AX BOOM ROTATION AXIS -   BR BOTTOM CHAMBER -   BX ARM ROTATION AXIS -   CX BUCKET ROTATION AXIS -   GR GROUND -   RR ROD CHAMBER -   RX SWING AXIS -   M IMAGING RANGE -   OA OPTICAL AXIS -   P IMAGE -   P11 IMAGE -   P12 IMAGE -   P13 IMAGE -   P14 IMAGE -   P15 IMAGE -   P3 VEHICLE DATA IMAGE -   P4 WORKING EQUIPMENT DATA IMAGE -   P5 LOAD DATA IMAGE -   P6 BUCKET DATA IMAGE -   Pa PUMP PORT -   Pb BOTTOM PORT -   Pc ROD PORT -   Pd TANK PORT -   Q1 FIRST OPERATING POSITION -   Q2 SECOND OPERATING POSITION -   Q3 STOP POSITION 

1. A work machine remote control system comprising: a sensor data reception unit configured to receive detection data of an attitude of working equipment included in a work machine operated by an operation signal from a remote place; an alarm control unit configured to output an alarm control signal when it is determined, based on the detection data, that the working equipment is approaching or has reached an end position in a movable range; and an alarm device provided in the remote place and configured to output an alarm based on the alarm control signal from the alarm control unit.
 2. The work machine remote control system according to claim 1, wherein when the working equipment is approaching the end position in an end zone including the end position in the movable range, a speed of the working equipment is reduced, and the alarm control unit outputs the alarm control signal when it is determined, based on the detection data, that the working equipment is approaching the end position in an alarm zone adjacent to the end zone.
 3. The work machine remote control system according to claim 2, wherein the alarm control unit outputs the alarm control signal when it is determined, based on the detection data, that the working equipment is approaching the end position in the end zone.
 4. The work machine remote control system according to claim 2, wherein the alarm control unit outputs the alarm control signal when it is determined, based on the detection data, that the working equipment has reached the end position.
 5. A work machine remote control system comprising: a sensor data reception unit configured to receive detection data related to working equipment included in a work machine operated by an operation signal from a remote place; an alarm control unit configured to output an alarm control signal when it is determined, based on the detection data, that a level of an impact acting on the working equipment is equal to or greater than a threshold; and an alarm device provided in the remote place from the work machine and configured to output an alarm based on the alarm control signal from the alarm control unit.
 6. The work machine remote control system according to claim 5, wherein the work machine includes a working equipment attitude sensor that detects an attitude of the working equipment, and the alarm control unit determines whether the level of the impact is equal to or greater than the threshold based on detection data of the working equipment attitude sensor.
 7. The work machine remote control system according to claim 6, wherein the work machine includes a hydraulic cylinder that drives the working equipment based on hydraulic oil supplied from a hydraulic pump, and a pressure sensor that detects a pressure of the hydraulic oil in the hydraulic cylinder, and the alarm control unit determines whether the level of the impact is equal to or greater than the threshold based on detection data of the pressure sensor. 